5vdc @ 50ma will drive a relay but may be intended to drive a solid
state relay which it would do easily. One would want to check that the
drive is suitable for driving an inductive load like a relay also, it
needs to be able to take the back EMF when the relay is de-energised or
may be damaged. You could of course add your own diode across the relay
to absorb the back EMF.

Mike Firth wrote:

I question whether this is appropriate - it seems to offer features you
don't need and seems inadequate in what you do need.
The specification .pdf file says
Control Output: 5 Vdc drive @ 50 mA max (internal 5 Vdc source)

This means that you will have to use 5 volt driven relays. The size that
will carry your amperage may pull enough milliamps that if you want to
double up relays to get capacity that you will exceed the 50ma. You may
have to buy a small 5VDC relay from Radio Shack (fortunately the 5 v supply
is in the controller) just to drive the contactors or bigger relays. The
contactors Omega sells seem to have 120 or 240 volt coils, so an
intermediate relay would be require.